I want to power my RPi with a lithium ion battery. The RPi will be powering some devices which require constant voltage to power them.

If I use a battery as supply for the RPi (which changes as it depletes), will the 3.3 or 5V pins still output a constant voltage?

I saw this post here: Does the Raspberry Pi 3 regulate the voltage on its 5V pins?

which seems to rule this out for the 5V pin, but I wasn't clear on the 3.3V pin, can anyone advise?

This post: https://raspberrypise.tumblr.com/post/144555785379/exploring-the-33v-power-rail

appears to confirm the constant 3.3V output, but would appreciate confirmation by someone with more experience

2 Answers 2


Practically speaking, you cannot power the RPi by a raw Li-Ion cell: its voltage will be in the range of 3..4.2V while the RPi requires 4.75V..5.25V. You will need to boost the Li-Ion cell voltage to 5V.


The Pi has an on-board regulator which supplies the many voltages it requires (including 3.3V) although different models achieve this by diverse means.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.